In the circuit and system theory and in practice it is of interest to minimize an impedance of interest. Further in order to achieve mathematically complete, and thus ideal, load independent operation, it can be shown that an impedance of interest should be forced to zero. All known techniques produce less or more successful minimization of the impedance of interest, usually in proportion to their complexity. None of the presently known techniques produces a zero impedance, except a synthesis methods described in a copending and coassigned applications by these two same inventors Lj. Dj. Varga and N. A. Losic, "Synthesis of Zero-Impedance Converter", Ser. No. 07/452,000, Dec. 1989, "Synthesis of Improved Zero-Impedance Converter" by N. A. Losic and Lj. Dj. Varga. Ser. No. 07/457,158, Dec. 1989, and "Parameter-Free Synthesis of Zero-Impedance Converter" by N. A. Losic and Lj. Dj. Varga, Ser. No. 07/484,494, Feb. 1990. A specific and particular applications of a zero-impedance converter, in addition to those in the applications above, are described in the U.S. Pat. No. 4,885,674 "Synthesis of Load-Independent Switch-Power Converters" by Lj. Dj. Varga and N. A. Losic, issued Dec. 1989, as well as in a two copending and coassigned applications of N. A. Losic and Lj. Dj. Varga, "Synthesis of Load-Independent DC Drive System", Ser. No. 07/323,630, Nov. 1988, and "Synthesis of Load-Independent AC Drive Systems", Ser. No. 07/316,664, Feb. 1989 (allowed for issuance Dec. 1989).
Another advantage due to the use of the zero-impedance converter, seen in creating possibility to reduce order of an electric motor drive system to zero by implementing appropriate (feed)forward algorithms if the system uses the zero-impedance converter (to produce a load independent operation), is explored and described in a copending application Ser. No. 07/468,122 by N. A. Losic and Lj. Dj. Varga "Synthesis of Drive Systems of Infinite Disturbance Rejection Ratio and Zero-Dynamics/Instantaneous Response", Jan. 1990. Furthermore, a generalized synthesis method to produce zero-order dynamics/instantaneous response and infinite disturbance rejection ratio in a general case of control systems of n-th order is described in a copending and coassigned application by Lj. Dj. Varga and N. A. Losic, "Generalized Synthesis of Control Systems of Zero-Order/Instantaneous Response and Infinite Disturbance Rejection Ratio", Ser. No. 07/479,275, Feb. 1990.
The zero-impedance converter and its particular and specific applications, as described in the patents/patent applications on behalf of these two inventors listed above, operate on a specific (given) values of a resistive and reactive parts of an impedance of interest, except in the patent application Ser. No. 07/484,494 listed above in which an algorithm based on current and voltage measurements is implemented.